During packet transmission over a network, packets may be occasionally lost. Accordingly, forward error coding (FEC) means are used as known in the art to generate and transmit additional packets, which can be used in a receiver to recover such lost packets.
FIG. 1 illustrates a Prior Art system for transmitting media packets having ProMpeg/SMPTE2022 FEC packets. A transmitter 11 sends serially transmitted packets 123, including data (D1, D2, D3 . . . ) and FEC (R1 . . . ) packets, over a network 12 to a receiver 13.
Data in 111 stream is formed into data to be transmitted 112, in matrix form. A FEC encoder 113 processes the data to generate, for example, a FEC packet R1 114. The data and FEC packets are transmitted through a stack 115. After being transferred through the network 2, serially received packets 124 arrive at receiver 13, with an exemplary lost data packet (D2). In receiver 13, the packets are received in a stack 135, and from there are transferred to a data buffer 136. A received FEC packet R1 134 is transferred to a FEC decoder 133, wherein a recovered D2 packet 137 is generated. The data out, received packets 138 include the lost packet D2, along with the rest of the packets.
A standard media delivery system comprises transmitter 11 and receiver 13 devices; and the media stream is transmitted using a Real Time Protocol (RTP) from the transmitter to the receiver. The referenced prior art system does not include built-in support for packet retransmission, as is performed with Data delivery protocols such as TCP.
Embodiments of the present invention provide an infrastructure and system to add retransmission capability to media delivery systems using an RTP Protocol, as described hereinbelow.